12.1 Monolithically Integrated Sub-63 fJ/b 8-Channel 256Gb/s Optical Transmitter with Autonomous Wavelength Locking in 45nm CMOS SOI

Optical links play a key role in many applications ranging from data centers to AI systems. Such links typically consist of a light source chip, a transmitter chip (which may be co-integrated with the light source), and a receiver chip. Photonic and electronic devices within optical transmitter/receiver systems are either monolithically integrated or hybrid integrated. While hybrid integration has the advantage of using a high performance dedicated photonic fabrication process and an advanced technology node for electronic integration, the packaging parasitic components could limit the system bandwidth and/or decrease the energy efficiency compared to the monolithic integration approach.